It sometimes is desirable to mark an object, web or sheet with an image. Although packaging may include various information, marking directly on the product or object may provide additional product identification, ornamentation, advertising or marketing. For materials in web form that are often used for packaging or made into products where it is desirable to include various information, marking directly on the web material may provide additional product identification, ornamentation, advertising or marketing. Sheets of material are used to convey information, and it is desirable to mark directly on such sheets.
Several techniques are known for coating or marking various types of substrates. Electrostatic processes represent one group of such techniques. For example, in the reprographics industry, two primary powder-based processes and a liquid-based process are sometimes used for creating images. Such processes may use either monocomponent or dual component development systems. In the dry dual component system, for example, a carrier powder and an imaging powder, also known as a toner, are used. The carrier typically is reused in the system; whereas the imaging powder may be depleted depending on the quantity of material used to create the image and is replenished from a reservoir or other source.
A particular type of such processes includes laser printer techniques in which an image is transferred to a relatively flat surface. Current processes are complex, using up to seven process steps. Furthermore, these processes cannot be used to directly mark heat-sensitive substrates or nonplanar surfaces, and these processes are wasteful of the marking powder.